SwRI demonstrates ultra-low emissions hydrogen-fueled engine

Southwest Research Institute (SwRI) has announced the successful development of a hydrogen-fueled Class-8 demonstration vehicle through its H2-ICE consortium. This initiative, launched in November 2022, brings together industry leaders to advance hydrogen engine technology aimed at achieving ultra-low emissions in heavy-duty applications.

The centerpiece of the H2-ICE consortium’s achievement is the Hydrogen Internal Combustion Engine (H2-ICE), designed to produce minimal nitrogen oxide (NOx) and carbon dioxide (CO2) emissions while delivering the torque and power required for heavy-duty use. The engine has met stringent emissions targets, including the California Air Resources Board’s (CARB) Ultra-Low NOx designation of 0.02 g/hp-hr.

“We aimed to align the program with the Environmental Protection Agency’s Phase-3 greenhouse gas policy, setting an ambitious timeline,” said Ryan Williams, SwRI Powertrain Engineering Division manager and the H2-ICE consortium’s program manager. “Our integration teams executed the plan smoothly, thanks to meticulous planning.”

Industry-wide collaboration

SwRI’s consortia serve as hubs for industry collaboration, drawing expertise from various members to overcome technical hurdles. The consortium converted an X15N natural gas engine from Cummins to run on port-injected hydrogen, using custom-built parts and prototype components from other members.

“From specially formulated lubricants to prototype components, this has truly been an industry-wide effort,” Williams added. “The support and collaboration of the consortium were critical to completing the demonstration vehicle in the short time frame.”

Performance and efficiency

The H2-ICE vehicle offers a zero-GHG solution for the long-haul trucking market, featuring a 370-horsepower engine producing 2025 Newton-meters of torque and achieving over 40% efficiency, peaking at 43%. The engine’s CO2 emissions are remarkably low, measuring about 1.5 grams per horsepower-hour (g/hp-hr).

SwRI also developed a novel aftertreatment system tailored to hydrogen exhaust, further reducing NOx emissions to 0.008 g/hp-hr, significantly below the 2027 EPA limit of 0.035 g/hp-hr.“The NOx emissions from the H2-ICE platform are at or below the best achieved in our previous diesel low-NOx programs,” said Chris Sharp, SwRI Institute engineer. “We expect near-zero tailpipe NOx emissions under nearly all operating conditions. I am proud of the team’s accomplishments and excited for the project’s future.”

The demonstration vehicle is showcased at the 2024 ACT Expo in Las Vegas from May 20-23, alongside other leading low-carbon and zero-emissions technologies. It will also be displayed at the California Hydrogen Leadership Summit on June 16-17 in Sacramento, California.